Various methods have been employed in the past to track product usage, purchase, or consumption from a dispensing apparatus such as a vending machine and the like. Various types of sensors or counters may be used to keep track of the number of products dispensed from such a machine. For example, each "drop" of a bottle, a can, or other item from a vending machine may be tracked. These "smart" vending machines can keep an accurate tally of the amount of product dispensed because the machine is a controlled environment, i.e., the product is not dispensed until the selection button is pushed and the sale is completed.
This type of "smart" technology, however, has not been applicable to track the sale of products merely placed on a store or a cooler shelf. The existing vending machine technology is not directly applicable because a consumer is free to pick up a product, inspect it, take it, or return it to the shelf and make a different selection, i.e., the shelf is not a controlled environment. For example, a consumer may pick up a bottle or can containing a carbonated soft drink off of a shelf and then return that bottle or can and make a different selection. The return of the bottle or can may inflate the number of items actually removed from the shelf if only the removals are counted or monitored.
What is needed therefore is a system and method for tracking the use, purchase, or consumption of items placed on a shelf. The system and method must be able to keep track of removals and additions to the shelf. Further, these systems and methods must be implemented in consumer friendly and/or otherwise non-obtrusive manner.